The people of the Comoros Islands have been voting in the final round of their presidential election.
Mr Azali is barred from seeking re-election
The voting got off to a slow start, as many polling stations opened late, but queues later formed.
More than 300,000 registered voters have been choosing between three candidates selected in the first round.
Following a 2001 constitutional settlement, the presidency rotates every four years between the three islands of the archipelago.
This time, all three candidates are from the island of Anjouan.
Frontrunner Ahmed Abdallah Mohamed Sambi is described as a moderate Islamist.
He is opposed by two secular candidates - Mohamed Djaanfari, a former military pilot, and Ibrahim Halidi, backed by outgoing President Azali Assoumani.
First peaceful change
Sunday's polls are being seen as a crucial test of the islands' power-sharing constitution.
If all goes according to plan, this will be the first peaceful change of government since independence from France almost 30 years ago, during which time the country has seen 19 coups and coup attempts.
Mr Azali, from Grand Comore, won the first election in 2002 after coming to power via a bloodless coup three years earlier.
The African Union has sent hundreds of mainly South African troops to help ensure a peaceful transition. Comoran troops have been confined to barracks.